This invention is an improved automatic transmission of the type described in U.S. Pat. Nos. 3,803,932 and 3,874,253 issued to Clive Waddington and known as a Waddington drive.
A Waddington drive comprises a rotatable input element having a cam which can assume varying eccentricities. The cam reciprocates a series of followers on crank arms connected to output gearing through one-way clutches. The cam eccentricity determines the displacement of the followers during a revolution and thereby sets the drive's speed and torque ratios. A control system is provided which automatically changes the speed and torque ratios so that the drive can be incorporated into a vehicle hub such as a bicycle for use as an automatic transmission.
It is an object of the present invention to provide a mechanically simpler Waddington drive than those described in the aforementioned issued patents. A further object is to provide a more compact drive more particularly adaptable to a bicycle.